diff --git a/src/test/settings_tests.cpp b/src/test/settings_tests.cpp
--- a/src/test/settings_tests.cpp
+++ b/src/test/settings_tests.cpp
@@ -4,8 +4,8 @@
 
 #include <util/settings.h>
 
-#include <test/util.h>
 #include <test/util/setup_common.h>
+#include <test/util/str.h>
 #include <util/strencodings.h>
 
 #include <univalue.h>
diff --git a/src/test/util.h b/src/test/util.h
--- a/src/test/util.h
+++ b/src/test/util.h
@@ -26,50 +26,6 @@
 std::shared_ptr<CBlock> PrepareBlock(const Config &config,
                                      const CScript &coinbase_scriptPubKey);
 
-/**
- * Increment a string. Useful to enumerate all fixed length strings with
- * characters in [min_char, max_char].
- */
-template <typename CharType, size_t StringLength>
-bool NextString(CharType (&string)[StringLength], CharType min_char,
-                CharType max_char) {
-    for (CharType &elem : string) {
-        bool has_next = elem != max_char;
-        elem =
-            elem < min_char || elem >= max_char ? min_char : CharType(elem + 1);
-        if (has_next) {
-            return true;
-        }
-    }
-    return false;
-}
-
-/**
- * Iterate over string values and call function for each string without
- * successive duplicate characters.
- */
-template <typename CharType, size_t StringLength, typename Fn>
-void ForEachNoDup(CharType (&string)[StringLength], CharType min_char,
-                  CharType max_char, Fn &&fn) {
-    for (bool has_next = true; has_next;
-         has_next = NextString(string, min_char, max_char)) {
-        int prev = -1;
-        bool skip_string = false;
-        for (CharType c : string) {
-            if (c == prev) {
-                skip_string = true;
-            }
-            if (skip_string || c < min_char || c > max_char) {
-                break;
-            }
-            prev = c;
-        }
-        if (!skip_string) {
-            fn();
-        }
-    }
-}
-
 // RPC-like //
 
 /** Import the address to the wallet */
diff --git a/src/test/util/str.h b/src/test/util/str.h
--- a/src/test/util/str.h
+++ b/src/test/util/str.h
@@ -9,4 +9,48 @@
 
 bool CaseInsensitiveEqual(const std::string &s1, const std::string &s2);
 
+/**
+ * Increment a string. Useful to enumerate all fixed length strings with
+ * characters in [min_char, max_char].
+ */
+template <typename CharType, size_t StringLength>
+bool NextString(CharType (&string)[StringLength], CharType min_char,
+                CharType max_char) {
+    for (CharType &elem : string) {
+        bool has_next = elem != max_char;
+        elem =
+            elem < min_char || elem >= max_char ? min_char : CharType(elem + 1);
+        if (has_next) {
+            return true;
+        }
+    }
+    return false;
+}
+
+/**
+ * Iterate over string values and call function for each string without
+ * successive duplicate characters.
+ */
+template <typename CharType, size_t StringLength, typename Fn>
+void ForEachNoDup(CharType (&string)[StringLength], CharType min_char,
+                  CharType max_char, Fn &&fn) {
+    for (bool has_next = true; has_next;
+         has_next = NextString(string, min_char, max_char)) {
+        int prev = -1;
+        bool skip_string = false;
+        for (CharType c : string) {
+            if (c == prev) {
+                skip_string = true;
+            }
+            if (skip_string || c < min_char || c > max_char) {
+                break;
+            }
+            prev = c;
+        }
+        if (!skip_string) {
+            fn();
+        }
+    }
+}
+
 #endif // BITCOIN_TEST_UTIL_STR_H
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -7,7 +7,7 @@
 #include <clientversion.h>
 #include <optional.h>
 #include <sync.h>
-#include <test/util.h>
+#include <test/util/str.h>
 #include <util/moneystr.h>
 #include <util/spanparsing.h>
 #include <util/strencodings.h>